Carroll E J, Acevedo-Duncan M, Justice R W, Santiago L
Adv Exp Med Biol. 1986;207:261-91. doi: 10.1007/978-1-4613-2255-9_16.
The sea urchin fertilization envelope (FE) is formed following initial sperm-egg interaction from the egg surface vitelline envelope (VE) and the paracrystalline protein fraction (PCF), derived from cortical granules. Although mature FEs are physicochemically hardened postinsemination, a major protein fraction consisting of seven major polypeptides was extracted from Strongylocentrotus purpuratus FEs and the major, separated components were immunologically cross-reactive with the principal polypeptides in PCF and isolated cortical granules. Antibodies prepared against extracted, core FEs were immunologically crossreactive with isolated VEs, but not with PCF, suggesting that only VE components are covalently crosslinked. Based on protease inhibitor experiments, our model of FE development is that a benzamidine-sensitive, cortical granule protease cleaves a 200 kD VE polypeptide during initial envelope elevation to set up the morphological change in FE papillae which occurs later. Divalent cations precipitate the PCF and form metal proteinate bridges between the VE and PCF. Based on peroxidase inhibitor experiments, we suggest that the cortical granule peroxidase crosslinks VE polypeptides, beginning at 2-3 min postinsemination, to restrict the permeability of the VE so that normal envelope thickening occurs. A 305 kD VE polypeptide was isolated and appears to be important in sperm-egg interaction based on inhibition of sperm binding and fertilization by antibodies against the purified polypeptide.
海胆受精膜（FE）在精子与卵子最初相互作用后由卵子表面的卵黄膜（VE）和源自皮质颗粒的副晶蛋白组分（PCF）形成。尽管成熟的受精膜在授精后会发生物理化学硬化，但从紫球海胆受精膜中提取出了一种由七种主要多肽组成的主要蛋白质组分，并且分离出的主要成分与PCF和分离出的皮质颗粒中的主要多肽具有免疫交叉反应性。针对提取的核心受精膜制备的抗体与分离出的卵黄膜具有免疫交叉反应性，但与PCF没有，这表明只有卵黄膜成分是共价交联的。基于蛋白酶抑制剂实验，我们提出的受精膜发育模型是，一种对苯甲脒敏感的皮质颗粒蛋白酶在受精膜最初隆起时切割一种200 kD的卵黄膜多肽，从而引发受精膜乳头随后出现的形态变化。二价阳离子使PCF沉淀，并在卵黄膜和PCF之间形成金属蛋白桥。基于过氧化物酶抑制剂实验，我们认为皮质颗粒过氧化物酶在授精后2 - 3分钟开始使卵黄膜多肽交联，以限制卵黄膜的通透性，从而使受精膜正常增厚。分离出一种305 kD的卵黄膜多肽，基于针对纯化多肽的抗体对精子结合和受精的抑制作用，该多肽似乎在精子与卵子相互作用中起重要作用。
